The present invention relates to an engine room arrangement for a vehicle, and in particular to an engine room arrangement having a controlled crush zone.
Modern motor vehicles are mostly designed such that the vehicle body frame may crush in a controlled manner with the aim of reducing the impact of a vehicle crash to the vehicle occupants. For instance, in the case of a motor vehicle having an engine room in a front end of the vehicle body, the engine unit behaves as a substantially rigid body at the time of a vehicle crash, and must be so considered in designing the crush pattern of the front end of the vehicle at the time of a vehicle crash. The engine unit is often incorporated with a transmission unit at a lower end thereof, and the transmission unit may define the extent of the fore-and-aft dimension of the engine/transmission assembly.
The capability of a vehicle body to absorb the impact energy at the time of a vehicle crash can be increased by extending the length of the front end of the vehicle, but this approach is incompatible with the desire to reduce the dimension of the vehicle body without reducing the space for the vehicle occupants. This inevitably requires the space for the engine room to be reduced. It is therefore important to maximize the available crush stroke of the engine room without increasing the length of the engine room.
In addition to the engine assembly, the wheel suspension system consists of relatively rigid members, and tends to be resistant against crushing. Similarly, the steering assembly also tends to be resistant against crushing. Conventionally, it was therefore necessary to deduct the dimensions of the wheel suspension system and the steering gear unit from the available crush stroke of the vehicle body, and there have been some difficulty in ensuring a sufficient crush stroke without undesirably increasing the length of the engine room and thereby reducing the available space for the passenger compartment.
In view of such problems of the prior art, a primary object of the present invention is to provide an engine room arrangement for a vehicle which minimizes the fore-and-aft dimension of the engine room of the vehicle while ensuring a sufficient crush stroke to ensure a required capability to absorb the impact energy of a vehicle crash.
A second object of the present invention is to provide an engine room arrangement for a vehicle which maximizes the capability of the vehicle body to absorb the impact energy of a vehicle crash without imposing any restriction on the design of the various functional assemblies provided in and around the engine room.
According to the present invention, these and other objects can be accomplished by providing an engine room arrangement for a vehicle body having a controlled crushable zone, comprising: an engine assembly mounted on a vehicle body in a lateral orientation; and a wheel suspension system arranged on either side of the vehicle body; the wheel suspension system being dimensioned and positioned so as to be contained within a fore-and-aft profile of the engine assembly.
Thus, the wheel suspension system which is considered to be too rigid to define a crush zone in case of a vehicle crash is contained within the profile of the engine assembly, and would not in any way reduce the crush zone of the vehicle body which is effective in absorbing the impact energy of a vehicle crash. In particular, in view of optimizing the mechanical stability of the wheel suspension system, it is desirable to maximize the fore-and-aft dimension thereof. It may be therefore preferable in some cases if the wheel suspension system is dimensioned and positioned so as to substantially coincide with the fore-and-aft profile of the engine assembly. For instance, the wheel suspension system comprises a lower arm having a base end pivotally attached to the vehicle body, and the base end defines a fore-and-aft dimension of the wheel suspension system.
A steering gear may also be too rigid to define a crush zone. To avoid the steering mechanism from reducing the effective crush zone, the engine assembly may comprise an engine unit and a transmission unit which is disposed under the engine unit so as to project toward a passenger compartment of the vehicle body, the steering gear unit being placed so as to oppose a recess defined above the transmission unit. Also, the upper end of the engine assembly often projects toward the passenger compartment due to the presence of an intake manifold. It is therefore preferable in such a case to place the steering gear unit so as to oppose a recess defined between the intake manifold and the transmission unit.
The tie rods conventionally extended along a relatively low part of the engine room, and therefore interfered with the transmission unit in case of a vehicle crash. Therefore, the wheel suspension system may comprise a knuckle arm extending upwardly so that the tie rod may extends substantially horizontally a relatively a high elevation between a free end of the knuckle arm and an output end of the steering gear unit. If conventional knuckle arms are used, the tie rods may then extend obliquely from the free end of the knuckle arms which are located at relatively low points to an output end of the steering mechanism which is located at a relatively high point.